<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>折扇</title>
    <style>
        ul{
            list-style: none;
            width: 400px;
            height: 300px;
            margin: 0 auto;
            margin-top: 100px;
            border: 2px dotted black;
            position: relative;
            
        }
        li{
            position:absolute;
            height: 100px;
            width: 20px;
            top: 50%;
            left: 50%;
            margin-left: -10px;
            bottom: 20px;
            border-radius: 5px;
            box-shadow: 3px 3px 3px gray ;
            color: white;
            transition: all linear 3s;
            transform-origin: bottom center;
            text-align: center;
        }
        ul li:nth-child(7){
            background: rgb(236, 169, 169);
        }
        ul li:nth-child(1) , li:nth-child(13){
            background: rgb(235, 229, 126);
        }
        ul li:nth-child(2) ,li:nth-child(12){
            background: rgb(175, 235, 126);
        }
        ul li:nth-child(3) ,li:nth-child(11){
            background: rgb(235, 171, 126);
        }
        ul li:nth-child(4) , li:nth-child(10){
            background: rgb(235, 217, 126);
        }
        ul li:nth-child(5) , li:nth-child(9){
            background: rgb(126, 235, 142);
        }
        ul li:nth-child(6) , li:nth-child(8){
            background: rgb(126, 235, 230);
        }
        ul li:not(:nth-child(7)){
            opacity: 0;
        }
        ul:hover li{
            opacity: 1;
        }
        
        ul:hover li:nth-child(1){
            transform: rotate(90deg);
            /* transform-origin: bottom center; 
            写在这里的话会从li的中心开始转，底部也会转*/
        }
        ul:hover li:nth-child(13){
            transform: rotate(-90deg);
            
        }
        ul:hover li:nth-child(2){
            transform: rotate(75deg);
            
        }
        ul:hover li:nth-child(12){
            transform: rotate(-75deg);
            
        }
        ul:hover li:nth-child(3){
            transform: rotate(60deg);
            
        }
        ul:hover li:nth-child(11){
            transform: rotate(-60deg);
            
        }
        ul:hover li:nth-child(4){
            transform: rotate(45deg);
            
        }
        ul:hover li:nth-child(10){
            transform: rotate(-45deg);
            
        }
        ul:hover li:nth-child(5){
            transform: rotate(30deg);
            
        }
        ul:hover li:nth-child(9){
            transform: rotate(-30deg);
            
        }
        ul:hover li:nth-child(6){
            transform: rotate(15deg);
            
        }
        ul:hover li:nth-child(8){
            transform: rotate(-15deg);
        }

        

    </style>
</head>
<body>
    <ul>
        <li>1</li>
        <li>2</li>
        <li>3</li>
        <li>4</li>
        <li>5</li>
        <li>6</li>
        <li>7</li>
        <li>8</li>
        <li>9</li>
        <li>10</li>
        <li>11</li>
        <li>12</li>
        <li>13</li>
    </ul>
</body>
</html>